Topic
Diffraction efficiency
About: Diffraction efficiency is a research topic. Over the lifetime, 10320 publications have been published within this topic receiving 158298 citations.
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TL;DR: In this article, the diffraction of light by deep rectangular-groove transmission phase gratings is treated by solving Maxwell's equations numerically, and results are given for the light diffracted into the zero order by gratings with grating constants d in the range λ < d < 5λ, aspect ratio b (= linewidth/d), 0 < b < 1, and grating depths a < 5 λ, assuming a refractive index n 0 = 1.
Abstract: The diffraction of light by deep rectangular-groove transmission phase gratings is treated by solving Maxwell’s equations numerically. Results are given for the light diffracted into the zero order by gratings with grating constants d in the range λ < d < 5λ, aspect ratio b (= linewidth/d), 0 < b < 1, and grating depths a < 5λ, assuming a refractive index n0 = 1.5. Such gratings are used in practice as a dye-free replacement for color filters. They offer a new way of storing pictorial information in small format for read out in conventional projectors.
322 citations
TL;DR: M/# is introduced as a metric for characterizing holographic memory systems and it is verified experimentally that the diffraction efficiency of multiple holograms follows the prediction of M/# measured from a single hologram.
Abstract: We introduce M/# as a metric for characterizing holographic memory systems. M/# is the constant of proportionality between diffraction efficiency and the number of holograms squared. Although M/# is a function of many variables in a holographic recording system, it can be measured from the recording and erasure of a single hologram. We verify experimentally that the diffraction efficiency of multiple holograms follows the prediction of M/# measured from a single hologram.
322 citations
20 Nov 2015
TL;DR: In this article, the authors describe two methods to create high-fidelity GPHs, one interferometric and another direct-write, capable of recording the wavefront of nearly any physical or virtual object.
Abstract: Throughout optics and photonics, phase is normally controlled via an optical path difference. Although much less common, an alternative means for phase control exists: a geometric phase (GP) shift occurring when a light wave is transformed through one parameter space, e.g., polarization, in such a way as to create a change in a second parameter, e.g., phase. In thin films and surfaces where only the GP varies spatially—which may be called GP holograms (GPHs)—the phase profile of nearly any (physical or virtual) object can in principle be embodied as an inhomogeneous anisotropy manifesting exceptional diffraction and polarization behavior. Pure GP elements have had poor efficiency and utility up to now, except in isolated cases, due to the lack of fabrication techniques producing elements with an arbitrary spatially varying GP shift at visible and near-infrared wavelengths. Here, we describe two methods to create high-fidelity GPHs, one interferometric and another direct-write, capable of recording the wavefront of nearly any physical or virtual object. We employ photoaligned liquid crystals to record the patterns as an inhomogeneous optical axis profile in thin films with a few μm thickness. We report on eight representative examples, including a GP lens with F/2.3 (at 633 nm) and 99% diffraction efficiency across visible wavelengths, and several GP vortex phase plates with excellent modal purity and remarkably small central defect size (e.g., 0.7 and 7 μm for topological charges of 1 and 8, respectively). We also report on a GP Fourier hologram, a fan-out grid with dozens of far-field spots, and an elaborate phase profile, which showed excellent fidelity and very low leakage wave transmittance and haze. Together, these techniques are the first practical bases for arbitrary GPHs with essentially no loss, high phase gradients (∼rad/μm), novel polarization functionality, and broadband behavior.
322 citations
TL;DR: Polarization holographic recording, based on photoinducing optical anisotropy in the recording material, is examined in this paper, where the properties (diffraction efficiency and selectivity) are discussed for two t
Abstract: Polarization holographic recording, based on photoinducing optical anisotropy in the recording material, is examined. The properties (diffraction efficiency and selectivity) are discussed for two t...
318 citations
14 Aug 1989
TL;DR: In this paper, the theory, design and fabrication of multi-level diffractive profiles are described in detail, and basic examples illustrate the potential usefulness, as well as the limitations of these elements.
Abstract: : Multi-level diffractive phase have the potential to significantly improved the performance of many conventional lens systems. The theory, design and fabrication of these diffractive profiles are described in detail. Basic examples illustrate the potential usefulness, as well as the limitations, of these elements. Keywords: Binary optics; Diffractive optical elements.
309 citations